In general, a flexible disc apparatus is proposed, which uses a flexible magnetic disc as a magnetic recording medium. The flexible disc apparatus uses one magnetic transducer head to carry out both the recording and playback. Such flexible disc apparatus has a disadvantage of mis-tracking caused by a little displacement of a magnetic recording medium upon installing (chucking), contraction and expansion of the magnetic recording medium due to the change of temperature and humidity of the environment. Particularly when the re-recording is carried out, the previously recorded data can not be fully erased due to the mis-tracking and so on. There is then a disadvantage that upon reproducing, accurate data can not be obtained.
As a recording and reproducing magnetic transducer head for such flexible disc apparatus, a magnetic transducer head for perpendicular recording mode previously proposed by the present applicant in the published document of the Japanese patent application unexamined No. 153216/1983 can be used, which is capable of carrying out the high density magnetic recording (short wavelength recording) and which can easily be produced as shown in FIG. 1. A magnetic transducer head H for perpendicular mode recording disclosed therein is formed such that a main magnetic pole 1 made of a thin film of soft magnetic material having a predetermined width to oppose at its one end a magnetic recording medium is sandwiched by guard blocks 2, 2' and integrated therewith. The guard blocks 2, 2' are respectively formed of non-magnetic guard members 3, 3' extended from the contact surface with the magnetic recording medium to a predetermined position and magnetic core members 4, 4' bonded to the lower surfaces thereof and extended to the rear sides thereof. In the magnetic core members 4, 4', there are formed auxiliary pole members 6, 6' bonded to the main magnetic pole 1 and wound therearound a coil 5 and grooves 8, 8' for magnetically separating the auxiliary pole members 6, 6' with return path portions 7, 7', each of which becomes a return path of a magnetic flux of the main magnetic pole 1. Within the grooves 8, 8', the coil 5 is wound around the main magnetic pole 1 through the auxiliary magnetic pole members 6, 6'. According to such magnetic transducer head for perpendicular mode recording it is possible to carry out the high density magnetic recording.
However, even when the magnetic transducer head for perpendicular mode recording as shown in FIG. 1 is used, the mis-tracking is caused by the displacement of the magnetic recording medium upon mounting the medium on the apparatus and the contraction and expansion of the magnetic recording medium due to the change of temperature and humidity so that upon rewriting, the previously recorded data can not be erased completely and so on. As a result, upon reproducing, the accurate data frequently could not be obtained In view of the above aspect, the present invention is to provide a magnetic transducer head for perpendicular mode recording in which even when the displacement of track is caused by the displacement of the magnetic recording medium upon mounting and the contraction and expansion of the magnetic recording medium due to the change of temperature and humidity, upon rewriting, it is possible to prevent the previously recorded data from not being erased completely, and thus obtain accurate data upon reproducing.